Project Summary/Abstract. Discovery and validation of strong candidate biomarkers and clinical endpoints for pain is urgently needed that can be used to facilitate the development of non-opioid pain therapeutics from discovery through Phase II clinical trials. Emerging research using a combination of biomarkers deliver individualized predictions about future brain and body health. Our own findings suggest that behavioral chronic pain characteristics are associated with multiple biological biomarkers where a greater pain burden is associated with accelerated detrimental biological processes. However, prospective research is urgently needed to determine pain?s impact on the heterogeneity of these biological processes within an individual to elucidate the underlying patterns of biological changes using a biobehavioral perspective which is needed for predicting future health and to be able to use as clinical endpoints for interventions. The proposed study will prospectively address biobehavioral factors (i.e., cognitive, psychological, social and cultural) affecting the experience and interpretation of knee pain and physical function across racial/ethnic groups over time. We will prospectively assess pain along with multiple biomarkers as predictors of cognitive, psychological and physical functional progression among middle-aged and older non- Hispanic Blacks and non-Hispanic Whites with knee pain and controls over a four-year study period. With strong support from the University of Florida, our interdisciplinary project, using a comprehensive biobehavioral multi- methods approach, we will be the first to prospectively determine the trajectory and interactions among pain, biological biomarkers and multiple domains of function within race/ethnic groups in OA pain. Findings will contribute towards increased understanding of pain and its biobehavioral basis, with the potential to reduce race/ethnic group disparities and improve pain-related health and functional outcomes.